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Biomedical subjects

P C Allen

Publications and source records attributed to P C Allen.

At least 55 records · Page 3Linked to original sources
PubMed1982

Changes in liver glycogen of broilers during coccidiosis.

Liver glycogen levels of broilers with Eimeria acervulina, E. Brunetti, or E. tenella fell during the acute phase of the infection with the maximum effect at 5-6 days post-inoculation (DPI). During the early recovery phase (6-8 DPI), liver glycogen levels in the E. acervulina-infected birds increased to levels up to 3 times greater than those found in uninoculated control birds. A lesser increase was occasionally seen in E. tenella-infected birds. Pair feeding studies showed that the decrease in liver glycogen was not related to the amount of feed consumed. The magnitude of the glycogen overshoot at 7 DPI was not related to the depression of weight gain at 5 and 6 DPI. When feed was withheld from birds, liver glycogen levels of uninoculated control birds fell rapidly within 1 h after feed withdrawal. In birds infected with E. acervulina, liver glycogen levels remained high even after 3 h starvation. Injection of glucagon indicated that glycogen could be mobilized in both infected and uninfected birds.

Animals↗
PubMed1981

Some heat engine cycles in which liquids can work.

Liquids can work in heat engine cycles that employ regeneration. Four such cycles are discussed: Stirling, Malone, Stirling-Malone, and Brayton. Both regeneration and the role of the second thermodynamic medium are treated, and the principles are verified by quantitative measurements with propylene in a Stirling-Malone cycle.

Journal Article↗
PubMed1981

Composition of heart, liver, and skeletal muscle from broilers with coccidiosis.

Infection with Eimeria acervulina, Eimeria brunetti, or Eimeria tenella affected the composition of the breast, thigh, heart, and liver of 3 or 4-week-old broilers. Liver glycogen was significantly increased at 6 and 8 days postinoculation (PI) with E. acervulina. Conversely, liver glycogen was decreased at 4 and 6 days PI with E. tenella and was unaffected by infection with E. brunetti. The levels of RNA and lipid in the liver were decreased with E. acervulina but unchanged with E. tenella. Both species decreased RNA levels in the breast. None of the three coccidial species had any effect on the moisture, ash, protein, or DNA content of the tissues.

Animals↗
PubMed1981

Analysis of liver glycogen in chicks.

The glycogen levels in homogenates from livers from 3- to 4-week-old broilers were measured using alkaline digestion and ethanol precipitation followed by direct hydrolysis with amyloglucosidase. Glycogen was determined with glucose oxidase. Glycogen levels were not affected by rapid freezing in liquid nitrogen and storage at -10 C. Glycogen was stabile at 4 C for at least 1 hr; however, at room temperature, over 50% of the glycogen was lost within 1 hr. Homogenization with .05 M ethylenediaminetetraacetate (EDTA) prevented this loss. Liver glycogen decreased rapidly (within 1 hr) after feed withdrawal and was sometimes undetectable within 2 hr. There was considerable variation in glycogen levels among individual birds. Liver glycogen levels were up to 50% higher at 1100 than at 0800 hr.

Analysis of Variance↗
PubMed1981

Clinical chemistry of anaplasmosis: blood chemical changes in infected mature cows.

The clinical chemical changes induced by Anaplasma marginale infection were determined in 16 adult, intact cows infected with either of 2 virulent isolates and in 8 others treated with a live sheep-attenuated A marginale vaccine and were compared with the clinical chemical analyses in 7 noninfected controls. Blood samples from the cows were analyzed for various serum components and during clinical disease. Cows infected with the 2 virulent isolates had maximum erythrocyte parasitemias (0.5% to 66%) between 1 and 11 days of patency (DP); 7 of the 16 infected animals died within 5 to 12 DP. Cows given the sheep-attenuated anaplasma vaccine had maximum parasitemias (0.1% to 4.2%) between 1 and 16 DP and none died. Infection with the virulent isolates produced severe anemia (mean RBC count = about 2 million/mm3) and caused increases in serum total bilirubin (TBILI), direct bilirubin (DBILI), serum urea nitrogen (SUN), alkaline phosphatase (ALP), and serum aspartate aminotransferase (AST) that were significantly higher than comparable changes in control values. These increases were highest after peak parasitemias in surviving animals. Vaccination with the attenuated isolate produced a mild anemia (mean RBC count = about 5 million/mm3) and a significant increase only in ALP. Marked increase in TBILI, DBILI, SUN, ALP, and AST were detected 0 to 1 day before death in 3 cows. However, such increases were not observed 2 to 4 days before death in the other cows that died.

Alkaline Phosphatase↗
PubMed1981

Clinical chemistry of anaplasmosis: comparative serum protein changes elicited by attenuated and virulent Anaplasma marginale isolates.

In a comparative study of the clinical chemical changes during Anaplasma marginale infection, 16 intact mature cows were infected with either of 2 virulent isolates. Eight others were treated with a live A marginale vaccine (sheep-attenuated) and 7 were maintained as controls. Before and during patency, samples of blood from the cows were analyzed for total WBC, parasitemia, card test titer (CTT), total protein, albumin, and globulin fractions. In the cows inoculated with virulent isolates, albumin was significantly depressed throughout patency, whereas gamma-globulins and WBC were increased after peak parasitemia, as well as during recovery. The CTT was highest immediately after peak parasitemia. A significant increase was not observed in beta-globulin. Seven of the 16 infected cows died, but no consistent patterns of change in serum protein fractions or WBC could be associated with mortality. The 8 cows vaccinated with the attenuated isolate showed a significant mean decrease in albumin throughout patency, but no significant mean increase in alpha- or beta-globulin. A mean increase in gamma-globulin was observed only during the recovery period. The CTT increased gradually throughout patency, peaking during the recovery period. A significant mean increase over control in WBC count was observed only during rising parasitemia.

Anaplasmosis↗
PubMed1980

Principles of liquids working in heat engines.

The thermodynamic and thermophysical properties of liquids suggest that they should be powerful working fluids in heat engines. Their use requires heat engines based conceptually on the Stirling and Malone principles. The principles are explained, and then experiments on propylene are presented that demonstrate the principles and confirm the thermodynamic analysis.

Journal Article↗
PubMed1979

An evaluation of Debrisan in chronic leg ulcers and pressure sores.

Debrisan (Dextranomer) was subjected to a simple open assessment in the treatment of fifty-three chronic leg ulcers and thirty pressure sores in eight hospitals. It was found that 70% of leg ulcers and 76% of pressure sores improved, with a noticeable cleansing effect being evident in 79% and 83% respectively. No side-effects were recorded.

Adult↗
PubMed1976

Effect of antiparasitic medication in ponies on pasture.

Twenty Shetland ponies, 6 to 7 months old, were naturally infected with gastrointestinal nematodes and stomach bots. The ponies were allotted to 2 groups of 10 and were maintained on separate similar pastures that were free of infective larvae at the beginning of the study. The ponies in 1 group were treated monthly for 17 months with a therapeutic dose of a thiabendazole and piperazine mixture; those in the other group were not treated. During the 3rd and 5th months of the experiment, the ponies in the treated group were also given therapeutic doses of dichlorvos to remove bots. Various physical, hematologic, parasitologic, and blood chemical observations were made at weekly intervals. Each group of ponies was weighed at biweekly intervals. At the end of the experiment, the greatest differences between the treated and control ponies were in the mean number of worm eggs in fecal samples (0 vs 1,866 eggs/g), mean body weight (151.9 vs 117.0 kg), mean heart girth (126.5 vs 116.3 cm), mean packed cell volume (36.4 vs 30.8%), and mean serum protein content (8.47 vs 9.33 mg/100 ml), especially beta-globulin content (mean of 1.9 vs 3.4 mg/100 ml). The treated ponies remained clinically normal and were more spirited and more difficult to restrain for blood sampling and weighing than were the untreated controls. Parasitic nematode larvae were not recovered from grass samples from the pasture grazed by the treated ponies, but many such larvae (up to 500/300-g sample) were recovered from grass samples from the pasture grazed by the untreated ponies.

Animals↗